There are known various techniques for horizontal continuous casting of metal (see a book by E. German, entitled "Continuous Casting", Metallurgizdat Publishers, Moscow, 1961, p. 168, FIG. 488; p. 170, FIG. 495; p. 200, FIG. 582), which consist in that a casting formed in a mold and a secondary-cooling zone is then withdrawn in a stepwise manner from the mold so as to be further severed to measured lengths.
A horizontal continuous-casting machine generally comprises a tundish, a cooled mold, a system for feeding molten metal into the mold, a secondary-cooling chamber, and a casting withdrawal mechanism.
The prior-art continuous casting processes are disadvantageous in that they fail to ensure the production of high-quality castings.
There is also known a process and apparatus for horizontal casting of metal (see a book by V. Shwarzmeier, entitled "Continuous Casting", Gosnauchtekhizdat Publishers, Moscow, 1962, p. 226) wherein a molten metal is fed into a horizontal mold by means of a closed sectional pipeline. The molten metal fed into the pipeline is raised to a level slightly above the mold, whereupon the metal is gravity fed into the mold to solidify therein, i.e. the casting process can be discontinued at will.
However, the above process also fails to ensure good quality of castings.
There is further known a process and apparatus for horizontal continuous casting of metal (see a book by O. A. Shatagin, V. G. Sladkoshteev et al., entitled "Horizontal Continuous Casting of Nonferrous Metals and Alloys", Metallurgizdat Publishers, Moscow, 1974, pp. 42-44, FIGS. 14-16). According to this process, a molten metal is fed into a mold from a holding furnace through a tightly closed tundish. The metal is delivered into the mold under pressure, which depends upon the height as measured from the metal meniscus to an opening in the horizontal mold. The casting formed in the mold is then withdrawn therefrom in a stepwise manner, passed through the secondary-cooling zone and finally cut to measured lengths.
The above-described process makes it impossible to control the initial stage of the casting formation or to improve the casting structure in cross section. The apparatus for performing this process is likewise unsuitable for improving the structure of the casting being produced.
There is also known a continuous casting process and apparatus as disclosed in USSR Inventor's Certificate No. 265385, which allow an overpressur to be built up in the liquid phase of the casting at intervals between the withdrawal cycles and a drop in pressure prior to the casting withdrawal operation, whereupon the casting is cooled in the secondary-cooling zone and then is cut to measured lengths. The apparatus for performing this process comprises a metal supply system including a tundish, an adapter with intercommunicating channels, a mold, a secondary-cooling chamber, a mechanism for intermittent withdrawal of the casting from the mold, and an arrangement for severing the casting into measured lengths.
The above described process and apparatus fail to ensure good quality of the cast product and make it impossible to set up favourable conditions for the formation of castings in the mold, for example, by producing pulsating pressure at the side of the molten metal on the solidifying skin of casting. Also, no provision is made for introducing a powdered material into the molten metal.